For all the Linux admins out there – Add this to the header of all your crontabs.
… and it becomes a lot clearer to anyone reading them…
# * * * * * command_to_be_executed # - - - - - # | | | | | # | | | | +----- day of the week (0 - 6) (Sunday=0) # | | | +--------- month (1 - 12) # | | +------------- day of the month (1 - 31) # | +----------------- hour (0 - 23) # +--------------------- min (0 - 59) # # Asterisk (*) any value # Comma (,) value list separator (0,20,30,45) # Dash (-) range of values (8-17) # Slash (/) steps values (*/20) # # @reboot Run once, at startup # @yearly Run once a year, "0 0 1 1 *" # @annually Same as @yearly # @monthly Run once a month, "0 0 1 * *" # @weekly Run once a week, "0 0 * * 0" # @daily Run once a day, "0 0 * * *" # @hourly Run once an hour, "0 * * * *"
Njoy!